Advances in traction methods for endoscopic submucosal dissection: What is the best traction method and traction direction?

Figure 16  Comparison of aerial and underwater endoscopic view. A: Severe fibrosis and halation makes the boundary between the submucosal layer and muscle layer unclear; B: Submergence enables a detailed observation through a natural zoom effect and causes halation disappearance, thereby clarifying the boundary between the submucosal layer and muscle layer. Citation: Nagata M. Usefulness of underwater endoscopic submucosal dissection in saline solution with a monopolar knife for colorectal tumors (with videos). Gastrointest Endosc 2018; 87(5): 1345-1353. Copyright © 2018 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc[20].